Method for manufacturing quantum dot layer, method for manufacturing luminescence device including the quantum dot layer, and display device including the quantum dot layer

ABSTRACT

A method for manufacturing a quantum dot layer including providing a substrate on which a first luminescence electrode, a second luminescence electrode, and a third luminescence electrode are disposed, providing a first mixed solution including a first quantum dot which has been surface-treated to have a first polarity, providing a second polarity opposite to the first polarity to the first luminescence electrode, disposing the first quantum dot on the first luminescence electrode, and drying the first mixed solution to form a first quantum dot layer.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from and the benefit of Korean PatentApplication No. 10-2019-0033616, filed on Mar. 25, 2019, which is herebyincorporated by reference for all purposes as if fully set forth herein.

BACKGROUND Field

Exemplary embodiments of the invention relate to a method formanufacturing a quantum dot layer, a method for manufacturing aluminescence device including the quantum dot layer, and a displaydevice including the quantum dot layer.

Discussion of the Background

Electronic devices, such as a mobile communication terminal, a digitalcamera, a laptop computer, a monitor, and a television include a displaydevice for displaying images.

In a display device, a quantum dot is actively used as a material for aluminescence device or for a light control layer. Typically, whenmanufacturing a luminescence device or light control layer whichincludes a quantum dot layer, a quantum dot is deposited by using a finemetal mask. However, when a quantum dot is deposited by using a finemetal mask, the mask may be warped as the mask area is widened, therebymaking it more difficult to manufacture a large display device, whilewasting material to increase process cost.

SUMMARY

Exemplary embodiments of the invention provide a method formanufacturing a quantum dot layer and a luminescence device includingthe quantum dot layer without a mask.

Exemplary embodiments of the invention also provide a display deviceincluding a quantum dot layer which is manufactured without using amask.

Additional features of the invention will be set forth in thedescription which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention.

An exemplary embodiment of the invention provides a method formanufacturing a quantum dot layer including: providing a substrate onwhich a first luminescence electrode, a second luminescence electrode,and a third luminescence electrode, which are spaced apart from eachother on a plane, are disposed; providing a first mixed solutionincluding a first quantum dot which has been surface-treated to have afirst polarity on the first to third luminescence electrodes; providinga second polarity opposite to the first polarity to the firstluminescence electrode; disposing the first quantum dot on the firstluminescence electrode on which the second polarity is provided; anddrying the first mixed solution to form a first quantum dot layer.

The providing of the first mixed solution on the first to thirdluminescence electrodes may include mixing a first base quantum dot witha base solution, which contains a polar material to prepare a firstmixed solution.

The method may further include: providing a second mixed solutionincluding a second quantum dot, which has been surface-treated to havethe first polarity on the first to third luminescence electrodes;providing the second polarity to the second luminescence electrode;disposing the second quantum dot on the second luminescence electrode,which is provided with the second polarity; drying the second mixedsolution to form a second quantum dot layer; providing a third mixedsolution including a third quantum dot, which has been surface-treatedto have the first polarity on the first to third luminescenceelectrodes; providing the second polarity to the third luminescenceelectrode; disposing the third quantum dot on the third luminescenceelectrode, which is provided with the second polarity; and drying thethird mixed solution to form a third quantum dot layer.

The method may further include disposing a second electrode on the firstto third quantum dot layers. The first quantum dot layer may emit redlight, the second quantum dot layer may emit green light, and the thirdquantum dot layer may emit blue light.

The first polarity may be a positive polarity. The polar material may bean organic compound having an amino group and a silane group.

The polar material may be at least one among3-aminopropyltriethoxysilane (APTES), 3-aminopropyltrimethoxysilane(APTMS), N-(6-aminohexyl)-3-aminopropyltrimethoxysilane (AHAPS),N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane (AEAPS),3-aminopropyldimethylethoxysilane (APMES), and3-(N,N-dimethyl)-aminopropyltrimethoxysilane (DMAPS).

The first polarity may be a negative polarity. The polar material may bean organic compound having a thiol group and a carboxyl group.

The polar material may be at least one selected from amongmercaptoacetic acid derivatives, mercaptopropionic acid derivatives,mercaptobutyric acid derivatives, and mercaptovaleric acid derivatives.

The first quantum dot layer may be a quantum dot layer, which absorbsblue light and emits red light or green light.

The substrate may have an optical transmittance of 90% or more.

The disposing of the first quantum dot may further include providing thefirst polarity to the second luminescence electrode and the thirdluminescence electrode.

Another exemplary embodiment of the invention provides a method formanufacturing a luminescence device including: providing a substrate onwhich a first electrode is disposed; providing a first mixed solutionincluding a quantum dot which has been surface-treated with a polarmaterial to have a first polarity on the first electrode; providing asecond polarity opposite to the first polarity to the first electrode;disposing the quantum dot on the first electrode on which the secondpolarity is provided; drying the first mixed solution to form a quantumdot layer; and disposing a second electrode on the quantum dot layer.

The polar material may be an organic compound having an amino group anda silane group, or a thiol group and a carboxyl group.

The polar material may be at least one selected from among3-aminopropyltriethoxysilane (APTES), 3-aminopropyltrimethoxysilane(APTMS), N-(6-aminohexyl)-3-aminopropyltrimethoxysilane (AHAPS),N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane (AEAPS),3-aminopropyldimethylethoxysilane (APMES), and3-(N,N-dimethyl)-aminopropyltrimethoxysilane (DMAPS). Alternatively, thepolar material may be at least one selected from among mercaptoaceticacid derivatives, mercaptopropionic acid derivatives, mercaptobutyricacid derivatives, and mercaptovaleric acid derivatives.

Another exemplary embodiment of the invention provides a display deviceincluding a first pixel area, a second pixel area, a third pixel area, afirst luminescence device, a second luminescence device, and a thirdluminescence device. The first luminescence device, the secondluminescence device, and the third luminescence device may have aone-to-one correspondence with the first pixel area, the second pixelarea, and the third pixel area, respectively. Each of the first to thirdluminescence devices may include a first electrode, a second electrode,and a quantum dot layer. The quantum dot layer may include a quantum dotwhich is disposed between the first electrode and the second electrode,and has been surface-treated with a polar material. The polar materialmay be an organic compound having an amino group and a silane group, ora thiol group and a carboxyl group.

The polar material may be at least one selected from among3-aminopropyltriethoxysilane (APTES), 3-aminopropyltrimethoxysilane(APTMS), N-(6-aminohexyl)-3-aminopropyltrimethoxysilane (AHAPS),N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane (AEAPS),3-aminopropyldimethylethoxysilane (APMES), and3-(N,N-dimethyl)-aminopropyltrimethoxysilane (DMAPS). Alternatively, thepolar material may be at least one selected from among mercaptoaceticacid derivatives, mercaptopropionic acid derivatives, mercaptobutyricacid derivatives, and mercaptovaleric acid derivatives.

Each of the first to third luminescence devices may further include anelectron transporting region and a hole transporting region. Theelectron transporting region may be disposed between the first electrodeand the quantum dot layer. The hole transporting region may furtherinclude a hole transporting region disposed between the quantum dotlayer and the second electrode.

The first luminescence device may emit red light, the secondluminescence device may emit green light, and the third luminescencedevice may emit blue light.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the inventive concepts, and are incorporated in andconstitute a part of this specification. The drawings illustrateexemplary embodiments of the inventive concept and, together with thedescription, serve to explain principles of the inventive concepts.

FIG. 1 is a perspective view of a display device according to anexemplary embodiment of the invention.

FIG. 2A is a flowchart of a method for manufacturing a quantum dot layeraccording to an exemplary embodiment.

FIG. 2B is a flowchart of a method for manufacturing a quantum dot layeraccording to an exemplary embodiment.

FIG. 3 is a flowchart of a method for manufacturing a luminescencedevice including a quantum dot layer according to an exemplaryembodiment.

FIG. 4 is a plan view of a display device according to an exemplaryembodiment.

FIG. 5A is a cross-sectional view illustrating a step for providing asubstrate on which first to third luminescence electrodes are formed.

FIG. 5B is a view illustrating a step for preparing a first mixedsolution.

FIG. 5C is a perspective view illustrating a quantum dot luminous bodywhich has been surface-treated with a polar material according to anexemplary embodiment.

FIG. 5D is a cross-sectional view illustrating a step for providing afirst mixed solution on first to third luminescence electrodes.

FIG. 5E is a cross-sectional view illustrating a step for providing asecond polarity to a first luminescence electrode.

FIG. 5F is a cross-sectional view illustrating a step for drying a firstmixed solution to form a first quantum dot layer.

FIG. 5G is a cross-sectional view illustrating a step for providing asecond mixed solution on first to third luminescence electrodes.

FIG. 5H is a cross-sectional view illustrating a step for providing asecond polarity to a second luminescence electrode.

FIG. 5I is a cross-sectional view illustrating a step for drying asecond mixed solution to form a second quantum dot layer.

FIG. 5J is a cross-sectional view illustrating a step for providing afirst polarity to a second luminescence electrode and a thirdluminescence electrode according to exemplary embodiment.

FIG. 5K is a cross-sectional view illustrating a substrate on which aquantum dot layer formed by a method for manufacturing a quantum dotlayer according to an exemplary embodiment is disposed.

FIG. 5L is a cross-sectional view illustrating a display device on whicha luminescence device formed by a method for manufacturing aluminescence device according to an exemplary embodiment is disposed.

FIG. 6 is a cross-sectional view illustrating a display device on whicha luminescence device formed by a method for manufacturing aluminescence device according to an exemplary embodiment is disposed.

DETAILED DESCRIPTION

In the following description, for the purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of various exemplary embodiments of the invention. As usedherein “embodiments” are non-limiting examples of devices or methodsemploying one or more of the inventive concepts disclosed herein. It isapparent, however, that various exemplary embodiments may be practicedwithout these specific details or with one or more equivalentarrangements. In other instances, well-known structures and devices areshown in block diagram form in order to avoid unnecessarily obscuringvarious exemplary embodiments. Further, various exemplary embodimentsmay be different, but do not have to be exclusive. For example, specificshapes, configurations, and characteristics of an exemplary embodimentmay be used or implemented in another exemplary embodiment withoutdeparting from the inventive concepts.

Unless otherwise specified, the illustrated exemplary embodiments are tobe understood as providing exemplary features of varying detail of someways in which the inventive concepts may be implemented in practice.Therefore, unless otherwise specified, the features, components,modules, layers, films, panels, regions, and/or aspects, etc.(hereinafter individually or collectively referred to as “elements”), ofthe various embodiments may be otherwise combined, separated,interchanged, and/or rearranged without departing from the inventiveconcepts.

The use of cross-hatching and/or shading in the accompanying drawings isgenerally provided to clarify boundaries between adjacent elements. Assuch, neither the presence nor the absence of cross-hatching or shadingconveys or indicates any preference or requirement for particularmaterials, material properties, dimensions, proportions, commonalitiesbetween illustrated elements, and/or any other characteristic,attribute, property, etc., of the elements, unless specified. Further,in the accompanying drawings, the size and relative sizes of elementsmay be exaggerated for clarity and/or descriptive purposes. When anexemplary embodiment may be implemented differently, a specific processorder may be performed differently from the described order. Forexample, two consecutively described processes may be performedsubstantially at the same time or performed in an order opposite to thedescribed order. Also, like reference numerals denote like elements.

When an element, such as a layer, is referred to as being “on,”“connected to,” or “coupled to” another element or layer, it may bedirectly on, connected to, or coupled to the other element or layer orintervening elements or layers may be present. When, however, an elementor layer is referred to as being “directly on,” “directly connected to,”or “directly coupled to” another element or layer, there are nointervening elements or layers present. To this end, the term“connected” may refer to physical, electrical, and/or fluid connection,with or without intervening elements. Further, the D1-axis, the D2-axis,and the D3-axis are not limited to three axes of a rectangularcoordinate system, such as the x, y, and z-axes, and may be interpretedin a broader sense. For example, the D1-axis, the D2-axis, and theD3-axis may be perpendicular to one another, or may represent differentdirections that are not perpendicular to one another. For the purposesof this disclosure, “at least one of X, Y, and Z” and “at least oneselected from the group consisting of X, Y, and Z” may be construed as Xonly, Y only, Z only, or any combination of two or more of X, Y, and Z,such as, for instance, XYZ, XYY, YZ, and ZZ. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items.

Although the terms “first,” “second,” etc. may be used herein todescribe various types of elements, these elements should not be limitedby these terms. These terms are used to distinguish one element fromanother element. Thus, a first element discussed below could be termed asecond element without departing from the teachings of the disclosure.

Spatially relative terms, such as “beneath,” “below,” “under,” “lower,”“above,” “upper,” “over,” “higher,” “side” (e.g., as in “sidewall”), andthe like, may be used herein for descriptive purposes, and, thereby, todescribe one elements relationship to another element(s) as illustratedin the drawings. Spatially relative terms are intended to encompassdifferent orientations of an apparatus in use, operation, and/ormanufacture in addition to the orientation depicted in the drawings. Forexample, if the apparatus in the drawings is turned over, elementsdescribed as “below” or “beneath” other elements or features would thenbe oriented “above” the other elements or features. Thus, the exemplaryterm “below” can encompass both an orientation of above and below.Furthermore, the apparatus may be otherwise oriented (e.g., rotated 90degrees or at other orientations), and, as such, the spatially relativedescriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments and is not intended to be limiting. As used herein, thesingular forms, “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. Moreover,the terms “comprises,” “comprising,” “includes,” and/or “including,”when used in this specification, specify the presence of statedfeatures, integers, steps, operations, elements, components, and/orgroups thereof, but do not preclude the presence or addition of one ormore other features, integers, steps, operations, elements, components,and/or groups thereof. It is also noted that, as used herein, the terms“substantially,” “about,” and other similar terms, are used as terms ofapproximation and not as terms of degree, and, as such, are utilized toaccount for inherent deviations in measured, calculated, and/or providedvalues that would be recognized by one of ordinary skill in the art.

Various exemplary embodiments are described herein with reference tosectional and/or exploded illustrations that are schematic illustrationsof idealized exemplary embodiments and/or intermediate structures. Assuch, variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, exemplary embodiments disclosed herein should notnecessarily be construed as limited to the particular illustrated shapesof regions, but are to include deviations in shapes that result from,for instance, manufacturing. In this manner, regions illustrated in thedrawings may be schematic in nature and the shapes of these regions maynot reflect actual shapes of regions of a device and, as such, are notnecessarily intended to be limiting.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure is a part. Terms,such as those defined in commonly used dictionaries, should beinterpreted as having a meaning that is consistent with their meaning inthe context of the relevant art and should not be interpreted in anidealized or overly formal sense, unless expressly so defined herein.

Hereinafter, exemplary embodiments of the invention will be describedwith reference to drawings.

FIG. 1 is a perspective view of a display device DD according to anexemplary embodiment of the invention. As illustrated in FIG. 1, thedisplay device DD may display an image IM through a display surface IS.The display surface IS is parallel to a plane defined by a firstdirection axis DR1 and a second direction axis DR2. A third directionaxis DR3 indicates a normal direction of the display surface IS, i.e., athickness direction of the display device DD.

A front surface (or a top surface) and a back surface (or a bottomsurface) of each member or unit which will be described below aredefined according to the third direction axis DR3. However, the first tothird direction axes DR1, DR2 and DR3 illustrated in FIG. 1 are merelyexemplary directions, and the directions indicated by the first to thirddirection axes DR1, DR2 and DR3 are relative concepts, so that thedirections may change into other directions. Hereinafter, the first tothird directions refer to the same reference numerals as the directionsindicated by the first to third direction axes DR1, DR2, and DR3,respectively.

In an exemplary embodiment of the invention, the display device DDhaving a planar display surface is illustrated, but the inventiveconcepts are not limited thereto. The display device DD may include acurved display surface or a stereoscopic display surface. Thestereoscopic display surface may include a plurality of display areasindicating different directions from each other, and may also include,for example, a polygonal columnar display surface.

The display device DD may be a rigid display device. However, theinventive concepts are not limited thereto, and the display device DDmay instead be a flexible display device DD. In this exemplaryembodiment, the display device DD applicable to a portable terminal isexemplarily illustrated. Although not illustrated herein, electronicmodules, a camera module, a power module, etc. mounted on a main boardare accommodated in a housing (not illustrated) to constitute theportable terminal. The display device DD according to the inventiveconcepts may be applied to not only a large-sized electronic device suchas a television, a monitor, but also a small- or medium-sized electronicdevice such as a tablet, a car navigation system, a game machine, asmart watch.

As illustrated FIG. 1, the display surface IS may include a display areaDA, in which the image IM is displayed, and a non-display area NDAadjacent to the display area DA. The non-display area NDA is an area inwhich the image is not displayed. As an example of the image IM, iconimages are illustrated in FIG. 1.

As illustrated in FIG. 1, the display area DA may have a rectangularshape. The non-display area NDA may surround the display area DA.However, the inventive concepts are not limited thereto, and the shapeof the display area DA and the shape of the non-display area NDA may berelatively designed.

The display device DD may include quantum dot layers EML1, EML2, andEML3, as shown in FIG. 5L. In addition, the display device DD mayinclude luminescence devices LD1, LD2, LD3, as shown in FIG. 5L,including the quantum dot layers EML1, EML2, and EML3. In this exemplaryembodiment, the quantum dot layers EML1, EML2, and EML3, may be used asan emission layer which emits light or used as a light control layerwhich converts a wavelength of light to a long wavelength or transmits awavelength of light.

FIGS. 2A and 2B are flowcharts of methods S1000 and S1100 formanufacturing quantum dot layers EML1, EML2, and EML3, according to anexemplary embodiment. FIGS. 5A to 5K are figures illustrating respectivesteps of the methods S1000 and S1100 for manufacturing the quantum dotlayers EML1, EML2, and EML3 according to an exemplary embodiment.

Referring to FIG. 2A, the method S1000 for manufacturing quantum dotlayers EML1, EML2, and EML3 may include: a step S110 for providing asubstrate SUB on which first to third luminescence electrodes EL1-1,EL1-2, and EL1-3 are formed; a step S111 for preparing a first mixedsolution SOL1 by mixing a first quantum dot QD1 with a solutioncontaining a polar material PM, a step S120 for providing the firstmixed solution SOL1 on the first to third luminescence electrodes EL1-1,EL1-2, and EL1-3; a step S130 for providing a second polarity to thefirst luminescence electrode EL1-1; a step S140 for disposing the firstquantum dot QD1 on the first luminescence electrode EL1-1; a step S150for drying the first mixed solution SOL1 to form a first quantum dotlayer EML1; a step S160 for providing a second mixed solution SOL2 onthe first to third luminescence electrodes EL1-1, EL1-2, and EL1-3; astep S170 for providing a second polarity to the second luminescenceelectrode EL1-2; a step S180 for disposing a second quantum dot QD2 onthe second luminescence electrode EL1-2; a step S190 for drying thesecond mixed solution SOL2 to form a second quantum dot layer EML2; astep S200 for providing a third mixed solution (not illustrated) on thefirst to third luminescence electrodes EL1-1, EL1-2, and EL1-3; a stepS210 for providing a second polarity to the third luminescence electrodeEL1-3; a step S220 for disposing a third quantum dot (not illustrated)on the third luminescence electrode EL1-3; and a step S230 for dryingthe third mixed solution to form a third quantum dot layer EML3.

Referring to FIG. 2B, the method S1100 for manufacturing quantum dotlayers EML1, EML2, and EML3 according to an exemplary embodiment mayfurther include a step S131 for providing a first polarity to the secondluminescence electrode EL1-2 and the third luminescence electrode EL1-3.

FIG. 3 is a flowchart of a method S1200 for manufacturing a luminescencedevice LD1 including a quantum dot layer EML1 according to an exemplaryembodiment.

A detailed description for the manufacturing methods S1000, S1100, andS1200 according to FIGS. 2A, 2B, and 3 will be described later.

FIG. 4 is a plan view of a display device DD according to an exemplaryembodiment. FIG. 4 illustrates the display device DD when viewed fromabove.

Referring to FIG. 4, in the display device DD, first pixel areas PXA1,second pixel areas PXA2, third pixel areas PXA3, and a non-pixel areaNPXA may be defined.

The first pixel areas PXA1 may be disposed along the first directionDR1, the second pixel areas PXA2 may be disposed along the firstdirection DR1, and the third pixel areas PXA3 may be disposed along thefirst direction DR1. The first pixel areas PXA1, the second pixel areasPXA2, and the third pixel areas PXA3 may be alternately disposed alongthe second direction DR2. For example, one first pixel area PXA1, onesecond pixel area PXA2, and one third pixel area PXA3 may besequentially disposed along the second direction DR2.

The non-pixel area NPXA may be an area disposed adjacent to the firstpixel areas PXA1, the second pixel areas PXA2, and the third pixel areasPXA3. The non-pixel region NPXA may set boundaries of the first pixelareas PXA1, the second pixel areas PXA2, and the third pixel areas PXA3.

The first to third pixel areas PXA1, PXA2, and PXA3 may include quantumdot layers EML1, EML2, and EML3 as a luminescence layer or a lightcontrol layer.

The first pixel areas PXA1 may provide a first color light, the secondpixel areas PXA2 may provide a second color light, and the third pixelareas PXA3 may provide a third color light. The first color light, thesecond color light, and the third color light may be light havingdifferent colors each other. For example, among the first to third colorlight, one may be blue light, another one may be red light, and theother one may be green light.

Hereinafter, the method S1000 for manufacturing quantum dot layers EML1,EML2, and EML3 of an exemplary embodiment will be described withreference to FIGS. 2A and 5A to 5K. FIGS. 5A to 5K may illustrate areascorresponding to cross-sections taken along a line I-I′ in FIG. 4.

FIG. 5A is a cross-sectional view illustrating a step S110 for providinga substrate SUB on which the first to third luminescence electrodesEL1-1, EL1-2, and EL1-3 in FIG. 2A are disposed. Referring to FIGS. 2Aand 5A, the substrate SUB may include a base substrate BS and a circuitlayer CL disposed on the base substrate BS. The circuit layer CL mayinclude a plurality of transistors connected to the first to thirdluminescence electrodes EL1-1, EL1-2, and EL1-3, respectively. The basesubstrate BS may be a silicon substrate, a plastic substrate, a glasssubstrate, an insulating film, or a laminated structure including aplurality of insulating layers.

The first to third luminescence electrodes EL1-1, EL1-2, and EL1-3,which are spaced apart from each other on a plane, may be disposed onthe substrate SUB. A pixel defining layer PDL between the first to thirdluminescence electrodes EL1-1, EL1-2, and EL1-3 may be disposed. In thespecification, ‘on a plane’ may mean that the display device DD isviewed in the third direction (DR3, thickness direction).

The pixel defining layer PDL may overlap a portion of the first to thirdluminescence electrodes EL1-1, EL1-2, and EL1-3 on a plane. Although notillustrated, the pixel defining layer PDL may be omitted.

FIG. 5B is a view illustrating a step S100 for preparing the first mixedsolution SOL1 in FIG. 2A.

Referring to FIGS. 5B and 2, a step S111 for preparing a first mixedsolution SOL1 by mixing a first quantum dot QD1 with a solution whichcontains a polar material PM. The number of the first quantum dots QD1per unit volume in the first mixed solution SOL1 may be adjusteddepending on area and thickness of the first quantum dot layer EML1 tobe formed.

When the first quantum dot QD1 is mixed with a solution containing thepolar material PM, the first quantum dot QD1 may be surface-treated dueto the polar material PM to exhibit a polarity.

For example, the polar material PM may react with and bond onto thesurface of the first quantum dot QD1 to modify the surface of the firstquantum dot QD1, and the surface of the first quantum dot QD1 mayexhibit a polarity due to the polarity of the polar material PM.Alternatively, the polar material PM may surround the surface of thefirst quantum dot QD1 to form a structure similar to a micellestructure, and accordingly, the surface of the first quantum dot QD1 mayexhibit a polarity. The polar material PM may be an organic compound.However, the inventive concepts are not limited thereto, and the polarmaterial PM may be a metal compound or an inorganic compound.

Although not illustrated, the first mixed solution SOL1 may contain anacid or a base. The acid or base may be a Bronsted-Lowry acid or aBronsted-Lowry base, respectively.

FIG. 5C is a perspective view illustrating a quantum dot QD which hasbeen surface-treated with a polar material PM according to an exemplaryembodiment. Referring to FIG. 5C, the quantum dot QD which has beensurface-treated with the polar material PM may include a base quantumdot QD-B and a polar material which surrounds the base quantum dot QD-B.

The base quantum dot QD-B may be a light-converting particle whichabsorbs incident light and emits light having a longer wavelength thanthe incident light. Alternatively, the base quantum dot QD-B may be aself-luminescence particle which is used as a self-luminescencematerial.

The base quantum dot QD-B, which has a crystal structure of severalnanometers in size and is formed of hundreds to thousands of atoms,exhibits a quantum confinement effect in which an energy band gap isincreased due to the small size thereof. When the base quantum dot QD-Bis irradiated with light having a wavelength higher than the band gapenergy, the base quantum dot QD-B is excited by absorbing the light andemits light having a specific wavelength to fall to a ground state. Thelight having the emitted wavelength has a value corresponding to theband gap. Luminescence characteristics caused by the quantum confinementeffect of the base quantum dot QD-B may be adjusted by adjusting sizeand composition thereof.

The base quantum dot QD-B may be selected from among a Group II-VIcompound, a Group III-V compound, a Group IV-VI compound, a Group IVelement, a Group IV compound, and a combination thereof.

The Group II-VI compound may be selected from the group consisting of abinary element compound selected from the group consisting of CdSe,CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, and acombination thereof; a ternary element compound selected from the groupconsisting of CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe,HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe,HgZnTe, MgZnSe, MgZnS, and a combination thereof; and a quaternaryelement compound selected from the group consisting of HgZnTeS, CdZnSeS,CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe,HgZnSTe, and a combination thereof.

The Group III-V compound may be selected from the group consisting of abinary element compound selected from the group consisting of GaN, GaP,GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, and acombination thereof; a ternary element compound selected from the groupconsisting of GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb,AlPAs, AlPSb, InGaP, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, and acombination thereof; and a quaternary element compound selected from thegroup consisting of GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs,GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb,and a combination thereof. The Group IV-VI compound may be selected fromthe group consisting of a binary element compound selected from thegroup consisting of SnS, SnSe, SnTe, PbS, PbSe, PbTe, and a combinationthereof; a ternary element compound selected from the group consistingof SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe,and a combination thereof; and a quaternary element compound selectedfrom the group consisting of SnPbSSe, SnPbSeTe, SnPbSTe, and acombination thereof. The Group IV element may be selected from the groupconsisting of Si, Ge, and a combination thereof. The Group IV compoundmay be a binary element compound selected from the group consisting ofSiC, SiGe, and a combination thereof.

At this time, the binary element compound, the ternary element compound,or the u) quaternary element compound may be present in a particle at auniform concentration, or may be present in the same particle in which aconcentration distribution is partially divided into different states.

The base quantum dot QD-B may be a core-shell structure, including acore CORE and a shell SHELL, which surrounds the core CORE. The basequantum dot QD-B may also have a core CORE/shell SHELL structure, inwhich one quantum dot surrounds the other quantum dot. An interfacebetween the core CORE and the shell SHELL may have a concentrationgradient, in which a concentration of the elements present in the shellSHELL becomes lowered toward the core.

In some exemplary embodiments, the base quantum dot QD-B may have acore-shell structure including a core which contains the describednanocrystal and a shell which surrounds the core. The shell of the basequantum dot QD-B may serve as a protective layer for maintainingsemiconductor characteristics by preventing chemical denaturation of thecore and/or as a charging layer for giving electrophoresischaracteristics to the base quantum dot QD-B. The shell may be a singlelayer or multiple layers. An interface between the core and the shellmay have a concentration gradient in which a concentration of theelements present in the shell becomes lowered toward the core. The shellof the base quantum dot QD-B may include, for example, a metal ornonmetal oxide, a semiconductor compound, or a combination thereof.

The metal or nonmetal oxide may include, for example, a binary elementcompound, such as SiO₂, Al₂O₃, TiO₂, ZnO, MnO, Mn₂O₃, Mn₃O₄, CuO, FeO,Fe₂O₃, Fe₃O₄, CoO, Co₃O₄, and NiO; or a ternary element compound such asMgAl₂O₄, CoFe₂O₄, NiFe₂O₄, and CoMn₂O₄, but the inventive concepts arenot limited thereto.

The base quantum dot QD-B may be a particle having a nanometer-scalesize. The base quantum dot QD-B may have a full width of half maximum(FWHM) of an emission wavelength spectrum of about 45 nm or less,preferably about 40 nm or less, more preferably about 30 nm or less, andcolor purity or color reproducibility may be improved in the describedrange. In addition, light emitted via the base quantum dots QD-B may beemitted in all directions, thereby improving a viewing angle of light.

Furthermore, a shape of the base quantum dots QD-B is not limited to aspecific shape typically used in the art, but more specifically,spherical, pyramidal, multi-arm, or cubic nanoparticles, nanotubes,nanowires, nanofibers, nanoplate particles, etc. may be used.

As illustrated in FIG. 5C, when the base quantum dot QD-B issurface-treated with the polar material PM, the polar material PM maysurround the surface of the shell SHELL of the base quantum dot QD-B.The polar material PM may either be directly bonded to the shell SHELLof the base quantum dot QD-B or surround the shell SHELL caused by theattraction force. The base quantum dot QD-B may have a first polaritydue to the polar material PM. The first polarity may have a positive ornegative polarity.

The polar material PM may have an amino group and a silane group. Thepolar material PM may be, for example, at least one among3-aminopropyltriethoxysilane (APTES), 3-aminopropyltrimethoxysilane(APTMS), N-(6-aminohexyl)-3-aminopropyltrimethoxysilane (AHAPS),N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane (AEAPS),3-aminopropyldimethylethoxysilane (APMES), and3-(N,N-dimethyl)-aminopropyltrimethoxysilane (DMAPS).

When the polar material PM has an amino group and a silane group, thesilane group may surround the base quantum dot QD-B. The amino group mayreceive hydrogen from the acid present in the mixed solution to form anammonium ion, and accordingly, the surface of the polar material PM mayexhibit a positive polarity.

The polar material PM may have a thiol group and a carboxylic group. Thepolar material PM may be, for example, at least one selected from amongmercaptoacetic acid derivatives, mercaptopropionic acid derivatives,mercaptobutyric acid derivatives, and mercaptovaleric acid derivatives.

When the polar material PM has a thiol group and a carboxyl group, thethiol group may surround the base quantum dot QD-B. The carboxyl groupmay provide hydrogen to the base present in the mixed solution to form acarboxyl anion, and accordingly, the surface of the polar material PMmay exhibit a negative polarity.

The described polar material PM is merely exemplary, and the material isnot particularly limited as long as imparting a polarity to the basequantum dot QD-B.

Furthermore, the mechanism through which the surface of the describedbase quantum dot QD-B exhibits a polarity is exemplary, and the basequantum dot QD-B may exhibit a polarity through other mechanismsdepending on the structure and kind of the polar material PM.

FIG. 5D is a cross-sectional view illustrating a step S160 for providingthe first mixed solution SOL1 in FIG. 2A on the first to thirdluminescence electrodes EL1-1, EL1-2, and EL1-3. FIG. 5E is across-sectional view illustrating a step S130 for providing a secondpolarity to the first luminescence electrode EL1-1 in FIG. 2A, and astep S140 for providing a first polarity to the second luminescenceelectrode EL1-2 and third luminescence electrode EL1-3 in FIG. 3.

Referring to FIGS. 2A, 5D, and 5E, the first mixed solution SOL1 may beprovided on the first to third luminescence electrodes EL1-1, EL1-2, andEL1-3. Thereafter, the second polarity opposite to the first polaritymay be provided to the first luminescence electrode EL1-1. A method forproviding the second polarity to the first luminescence electrode EL1-1is not particularly limited, and various methods which are easily usedby those skilled in the art may be used.

When the second polarity is provided to the first luminescence electrodeEL1-1, an attraction force may occur between a first quantum dot QD1which has been surface-treated with a polar material to have a firstpolarity and the first luminescence electrode EL1-1. Accordingly, thefirst quantum point QD1 may be disposed on the first luminescenceelectrode EL1-1. At this time, since the second luminescence electrodeEL1-2 and the third luminescence electrode EL1-3 do not have a secondpolarity, the first quantum dot QD1 may not be disposed.

FIG. 5F is a cross-sectional view illustrating a step S150 for dryingthe first mixed solution SOL1 in FIG. 2A to form a first quantum dotlayer EML1. Referring to FIGS. 2A and 5F, the first mixed solution SOL1may be dried to form the first quantum dot layer EML1. When the firstmixed solution SOL1 is dried, the first quantum dot QD1 may be fixed onthe first luminescence electrode EL1-1 to form the first quantum dotlayer EML1.

The time and temperature of drying are not particularly limited, and maybe adjusted depending on the volume of the first mixed solution SOL1 andthe number of the first quantum dots QD1 per unit volume of the firstmixed solution SOL1.

Although not illustrated, before the step S160 for providing the firstmixed solution SOL1 on the first to third luminescence electrodes EL1-1,EL1-2, and EL1-3, a step for disposing a hole transporting region HTR(FIG. 6) on the luminescence electrodes EL1-1, EL1-2, and EL1-3 may befurther included. In addition, after the drying step, a step for curingor coating the first quantum dot layer EML1 may be further included.

FIG. 5G is a cross-sectional view illustrating a step S160 for providingthe second mixed solution SOL2 in FIG. 2A on the first to thirdluminescence electrodes EL1-1, EL1-2, and EL1-3. FIG. 5H is across-sectional view illustrating a step S170 for providing a secondpolarity to the second luminescence electrode EL1-2 in FIG. 2A. FIG. 5Iis a cross-sectional view illustrating a step S180 for drying the secondmixed solution SOL2 in FIG. 2A to form a second quantum dot layer EML2.

Substantially the same contents as those described in FIGS. 5D to 5F maybe applied to the respective steps illustrated in FIGS. 5G to 5I, andaccordingly, a detailed description will be omitted.

Referring to FIG. 2A, a method S1000 for manufacturing quantum dotlayers EML1, EML2, and EML3 may include: a step S200 for providing athird mixed solution (not illustrated) on the first to thirdluminescence electrodes EL1-1, EL1-2, and EL1-3; a step S210 forproviding a second polarity to the third luminescence electrode EL1-3; astep S220 for disposing the third quantum dot (not illustrated) on thethird luminescence electrode EL1-3; and a step S230 for drying the thirdmixed solution to form a third quantum dot layer EML3.

To the step S200 for providing a third mixed solution (not illustrated)on the first to third luminescence electrodes EL1-1, EL1-2, and EL1-3,the step S210 for providing a second polarity to the third luminescenceelectrode EL1-3, the step S220 for disposing the third quantum dot (notillustrated) on the third luminescence electrode EL1-3, and the stepS230 for drying the third mixed solution to form a third quantum dotlayer EML3, substantially the same contents as those described in thesteps S120, S130, S140, and S150 illustrated in FIGS. 5E to 5F may beapplied, and accordingly, a detailed description will be omitted.

Although not illustrated, after the step S230 for drying the third mixedsolution (not illustrated) to form the third quantum dot layer EML3, astep for disposing an electron transporting region ETR (FIG. 6) on thefirst to third quantum dot layers EML1, EML2, and EML3 may be furtherincluded.

Hereinafter, a method S1100 for manufacturing quantum dot layers EML1,EML2, and EML3 according to an exemplary embodiment will be describedwith reference to FIGS. 2B and 5J.

FIG. 5J is a cross-sectional view illustrating a step for providing afirst polarity to the second luminescence electrode EL1-2 and the thirdluminescence electrode EL1-3 according to an embodiment.

Referring to FIGS. 2B and 5J, the method S1100 for manufacturing thequantum dot layers EML1, EML2, and EML3 according to an exemplaryembodiment may further include a step S131 for providing a firstpolarity to the second luminescence electrode EL1-2 and the thirdluminescence electrode EL1-3. The step S131 for providing a firstpolarity to the second luminescence electrode EL1-2 and the thirdluminescence electrode EL1-3 may be performed together with the stepS130 for providing a second polarity to the first luminescence electrodeEL1-1.

The first quantum dot QD1 of this exemplary embodiment issurface-treated with a polar material PM to have a first polarity.Accordingly, when the first polarity is provided to the secondluminescence electrode EL1-2 and third luminescence electrode EL1-3, arepulsive force may occur between the second luminescence electrodeEL1-2 and third luminescence electrode EL1-3, and the first quantum dotQD1. Accordingly, the first quantum dot QD1 may not be disposed on thesecond luminescence electrode EL1-2 and third luminescence electrodeEL1-3, but may be disposed only on the first luminescence electrodeEL1-1. Therefore, the first quantum dot QD1 may be selectively disposedonly on the first luminescence electrode EL1-1.

Although not illustrated, even when each of the second quantum dot QD2and the third quantum dot (not illustrated) is formed on the secondluminescence electrode EL1-2 and the third luminescence electrode EL1-3,substantially the same contents as those described above may be applied.

FIG. 5K is a cross-sectional view illustrating a substrate SUB on whichquantum dot layers EML1, EML2, and EML3, which are formed by the methodsS1000 and S1100 for manufacturing quantum dot layers EML1, EML2, andEML3 according to an exemplary embodiment, are disposed.

Referring to FIG. 5K, first to third pixel areas PXA1, PXA2, and PXA3and a non-pixel area NPXA may be defined by a pixel defining layer PDL.The pixel defining layer PDL may prevent colors from mixing between thefirst pixel areas PXA1, the second pixel areas PXA2, and the third pixelareas PXA3.

The first quantum dot layer EML1 may overlap the first pixel area PXA1on a plane, the second quantum dot layer EML2 may overlap the secondpixel area PXA2 on a plane, and the third quantum dot layer EML3 mayoverlap the third pixel area PXA3 on a plane.

The same contents as those described in FIG. 4 may be applied to thefirst to third pixel areas PXA1, PXA2, and PXA3.

The substrate SUB on which the quantum dot layers EML1, EML2, and EML3according to an exemplary embodiment are disposed may be disposed on anopposite substrate (not illustrated) on which a separate light-source isdisposed. At this time, the separate light-source is not particularlylimited, but may be an organic electroluminescence device emitting bluelight.

At this time, the quantum dot layers EML1, EML2, and EML3 may serve as alight control layer which absorbs light having a short wavelengthemitted from the separate light-source and emits light having a longwavelength. When blue light is emitted from the separate light-source,for example, the first quantum dot layer EML1 may absorb blue light toemit green light or red light. Alternatively, blue light which has acentral wavelength different from the blue light emitted from theseparate light-source may be emitted.

Referring to FIG. 5K, although FIG. 5K illustrates such that the quantumdot layers EML1, EML2, and EML3 are all formed, but in an exemplaryembodiment, only two among the quantum dot layers may be formed. Forexample, only the first quantum dot layer EML1 and the second quantumdot layer EML2 may be formed. At this time, the area corresponding tothe third quantum dot layer EML3 may be an area which transmits lightemitted from the separate light-source.

The substrate SUB on which the quantum dot layers EML1, EML2, and EML3are disposed may be a transparent substrate having an opticaltransmittance of 90% or more. Accordingly, when light is emitted to theoutside from the quantum dot layers EML1, EML2, and EML3, the amount ofthe light loss caused by passing through the substrate SUB may beminimized. When necessary, a portion of the substrate SUB may be removedby etching, for example.

The first to third luminescence electrodes EL1-1, EL1-2, and EL1-3 whichare disposed under the quantum dot layers EML1, EML2, and EML3 may betransmissive electrodes. The first to third luminescence electrodesEL1-1, EL1-2, and EL1-3 may include transparent metal oxides such asindium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), andindium tin zinc oxide (ITZO).

Hereinafter, a method S1200 for manufacturing a luminescence device LD1including a quantum dot layer EML1 will be described with reference toFIGS. 3 and 5L.

FIG. 5L is a cross-sectional view illustrating a display device DD inwhich luminescence devices LD1, LD2, and LD3 formed by the method S1200for manufacturing a luminescence device according to an exemplaryembodiment are disposed.

Referring to FIG. 3, the method S1200 for manufacturing a firstluminescence device LD1 including a quantum dot layer EML1 may include:a step S110-1 for providing a substrate on which a first luminescenceelectrode EL1-1 is disposed; a step S120-1 for providing a first mixedsolution SOL1 containing a quantum dot QD1 which has beensurface-treated with a polar material PM to have a first polarity on thefirst luminescence electrode EL1-1; a step S130-1 for providing a secondpolarity to the first luminescence electrode EL1-1; a step S140-1 fordisposing the quantum dot QD1 on the first luminescence electrode EL1-1,a step S150-1 for drying the first mixed solution SOL1 to form a quantumdot layer EML1; and a step S240 for disposing a second electrode EL2 onthe quantum dot layer EML1.

The steps S110-1, S120-1, S130-1, S140-1, and S150-1 respectivelycorrespond to the steps S110, S120, S130, S140, and S150 illustrated inFIG. 2, and substantially the same description may be applied.

Although the description of the method for manufacturing a secondluminescence device LD2 and a third luminescence device LD3 illustratedin FIG. 5L is omitted in FIG. 3, the same description of the methodS1200 for manufacturing a first luminescence device LD1 may be applied.For example, after the first to third quantum dot layers EML1, EML2, andEML3 are all formed, the second electrode EL2 may be disposed on thefirst to third quantum dot layers EML1, EML2, and EML3 to manufacturethe first to third luminescence devices LD1, LD2, and LD3.

Since the method S1200 for manufacturing the luminescence device LD1including the quantum dot layer EML1 of this exemplary embodimentincludes the step S240 for disposing the second electrode EL2 on thequantum dot layer EML1, the quantum dot layer EML1, which serves as anemission layer, may be formed.

Referring to FIG. 5L, the quantum dot layers EML1, EML2, and EML3 in theluminescence devices LD1, LD2, and LD3 may serve as an emission layer inan exemplary embodiment.

As the voltages are applied to the first to third luminescenceelectrodes EL1-1, EL1-2, and EL1-3, and the second electrode EL2,respectively, the holes injected from the first to third luminescenceelectrodes EL1-1, EL1-2, and EL1-3 may be moved to the quantum dotlayers EML1, EML2, and EML3, and the electrons injected from the secondelectrode EL2 may also be moved to the quantum dot layers EML1, EML2,and EML3. The electrons and holes may be recombined in the quantum dotlayers EML1, EML2, and EML3 to generate excitons, and the excitons mayemit light as the excitons fall back from the excited state to theground state.

At this time, the first quantum dot layer EML1 may emit red light, thesecond quantum dot layer EML2 may emit green light, and the thirdquantum dot layer EML3 may emit blue light.

The second electrode EL2 may be a transmissive electrode. The secondelectrode EL2 may include transparent metal oxides such as indium tinoxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), and indium tinzinc oxide (ITZO).

The display device DD in which the luminescence devices LD1, LD2, andLD3 manufactured by the method S1200 for manufacturing luminescencedevices LD1, LD2, and LD3, which include the quantum dot layers EML1,EML2, and EML3, are disposed, may emit the quantum dots, which are aluminescence material, by recombining the holes and electrons injectedfrom the first to third luminescence electrodes EL1-1, EL1-2, and EL1-3,and the second electrode in the quantum dot layers EML1, EML2, and EML3.At this time, each of the first to third luminescence electrodes EL1-1,EL1-2, and EL1-3 may be a transflective electrode or a reflectiveelectrode. The first to third luminescence electrodes EL1-1, EL1-2, andEL1-3 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca,LiF/Ca, LiF/Al, Mo, Ti, or a compound or a mixture thereof (for example,a mixture of Ag and Mg). Alternatively, the electrodes may have astructure which has a plurality of layers including: a reflective layeror a transflective layer formed of any among the described materials;and a transparent conductive layer formed of indium tin oxide (ITO),indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO),etc.

FIG. 6 is a cross-sectional view illustrating a display device DD inwhich luminescence devices LD1, LD2, and LD3 formed by the method S1200for manufacturing luminescence devices LD1, LD2, and LD3 according to anexemplary embodiment are disposed. Referring to FIG. 6, each of theluminescence devices LD1, LD2, and LD3 may further include a holetransporting region HTR and an electron transporting region ETR.

The first luminescence device LD1 may include a first quantum dot layerEML1 and emit red light, the second luminescence device LD2 may includea second quantum dot layer EML2 and emit green light, and the thirdluminescence device LD3 may include a third quantum dot layer EML3 andemit blue light.

The luminescence devices LD1, LD2, and LD3 may be manufactured by themethod S1200 for manufacturing luminescence devices LD1, LD2, and LD3which include the described quantum dot layers EML1, EML2, and EML3.Accordingly, the quantum dot layers EML1, EML2, and EML3 including thequantum dot QD, which has been surface-treated with a polar material PM,may be included.

The hole transporting region HTR may be disposed between the first tothird luminescence electrodes EL1-1, EL1-2, and EL1-3 and the quantumdot layers EML1, EML2, and EML3, respectively. The hole transportingregion HTR may include a hole transporting material and may have afunction of effectively transporting holes injected from the first tothird luminescence electrodes EL1-1, EL1-2, and EL1-3 to the quantum dotlayers EML1, EML2, and EML3.

The electron transporting region ETR may be disposed between the quantumdot layers EML1, EML2, and EML3 and the second electrode EL2,respectively. The electron transporting region ETR may include anelectron transporting material and may have a function of efficientlytransporting electrons injected from the second electrode EL2 to thequantum dot layers EML1, EML2, and EML3.

In the methods S1000, S1100, and S1200 for manufacturing a quantum dotlayer EML1 according to an exemplary embodiment and manufacturing aluminescence device LD1 which includes the quantum dot layer EML1, sincethe quantum dot QD which has been surface-treated with a polar materialPM to have a first polarity is disposed on the luminescence electrodeEL1-1 which is provided with a second polarity opposite to the firstpolarity, a quantum dot layer EML1 and a luminescence device LD1including the quantum dot layer EML1 may be manufactured without a mask.In addition, the display device DD according to an exemplary embodimentmay be manufactured without using a mask. Accordingly, the large displaydevice may be easily manufactured, and the process cost may be reduced.

According to a method for manufacturing a quantum dot layer according toan exemplary embodiment and a luminescence device which includes thequantum dot layer, a large display device may be manufactured.

According to a method for manufacturing a quantum dot layer according toan exemplary embodiment and a luminescence device which includes thequantum dot layer, process cost may be reduced.

A display device according to an exemplary embodiment may bemanufactured without using a mask.

Although certain exemplary embodiments have been described herein, otherembodiments and modifications will be apparent from this description.Accordingly, the inventive concepts are not limited to such embodiments,but rather to the broader scope of the appended claims and variousobvious modifications and equivalent arrangements as would be apparentto a person of ordinary skill in the art.

What is claimed is:
 1. A method for manufacturing a quantum dot layer,the method comprising: providing a substrate on which a firstluminescence electrode, a second luminescence electrode, and a thirdluminescence electrode, which are spaced apart from each other on aplane, are disposed; providing a first mixed solution including a firstquantum dot, which has been surface-treated to have a first polarity, onthe first to third luminescence electrodes; providing a second polarityopposite to the first polarity to the first luminescence electrode;disposing the first quantum dot on the first luminescence electrode onwhich the second polarity is provided; and drying the first mixedsolution to form a first quantum dot layer.
 2. The method of claim 1,wherein the providing of the first mixed solution on the first to thirdluminescence electrodes includes mixing a first base quantum dot with abase solution which contains a polar material to prepare a first mixedsolution.
 3. The method of claim 1, further comprising: providing asecond mixed solution including a second quantum dot which has beensurface-treated to have the first polarity on the first to thirdluminescence electrodes; providing the second polarity to the secondluminescence electrode; disposing the second quantum dot on the secondluminescence electrode, which is provided with the second polarity;drying the second mixed solution to form a second quantum dot layer;providing a third mixed solution including a third quantum dot, whichhas been surface-treated to have the first polarity, on the first tothird luminescence electrodes; providing the second polarity to thethird luminescence electrode; disposing the third quantum dot on thethird luminescence electrode, which is provided with the secondpolarity; and drying the third mixed solution to form a third quantumdot layer.
 4. The method of claim 2, wherein the first polarity is apositive polarity.
 5. The method of claim 4, wherein the polar materialis an organic compound having an amino group and a silane group.
 6. Themethod of claim 5, wherein the polar material is at least one selectedfrom the group consisting of 3-aminopropyltriethoxysilane (APTES),3-aminopropyltrimethoxysilane (APTMS),N-(6-aminohexyl)-3-aminopropyltrimethoxysilane (AHAPS),N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane (AEAPS),3-aminopropyldimethylethoxysilane (APMES), and3-(N,N-dimethyl)-aminopropyltrimethoxysilane (DMAPS).
 7. The method ofclaim 2, wherein the first polarity is a negative polarity.
 8. Themethod of claim 7, wherein the polar material is an organic compoundhaving a thiol group and a carboxyl group.
 9. The method of claim 8,wherein the polar material is at least one selected from the groupconsisting of mercaptoacetic acid derivatives, mercaptopropionic acidderivatives, mercaptobutyric acid derivatives, and mercaptovaleric acidderivatives.
 10. The method of claim 1, wherein the first quantum dotlayer absorbs blue light and emits red light or green light.
 11. Themethod of claim 1, wherein the substrate has an optical transmittance ofat 90% or more.
 12. The method of claim 1, wherein the disposing of thefirst quantum dot further comprises providing the first polarity to thesecond luminescence electrode and the third luminescence electrode. 13.The method of claim 3, further comprising disposing a second electrodeon the first to third quantum dot layers, wherein the first quantum dotlayer emits red light, the second quantum dot layer emits green light,and the third quantum dot layer emits blue light.
 14. A method formanufacturing a luminescence device, the method comprising: providing asubstrate on which a first electrode is disposed; providing a firstmixed solution including a quantum dot which has been surface-treatedwith a polar material to have a first polarity on the first electrode;providing a second polarity opposite to the first polarity to the firstelectrode; disposing the quantum dot on the first electrode on which thesecond polarity is provided; drying the first mixed solution to form aquantum dot layer; and disposing a second electrode on the quantum dotlayer.
 15. The method of claim 14, wherein the polar material is anorganic compound having an amino group and a silane group, or a thiolgroup and a carboxyl group.
 16. The method of claim 15, wherein: thepolar material is at least one selected from the group consisting of3-aminopropyltriethoxysilane (APTES), 3-aminopropyltrimethoxysilane(APTMS), N-(6-aminohexyl)-3-aminopropyltrimethoxysilane (AHAPS),N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane (AEAPS),3-aminopropyldimethylethoxysilane (APMES), and3-(N,N-dimethyl)-aminopropyltrimethoxysilane (DMAPS), or the polarmaterial is at least one selected from the group consisting ofmercaptoacetic acid derivatives, mercaptopropionic acid derivatives,mercaptobutyric acid derivatives, and mercaptovaleric acid derivatives.17. A display device including a first pixel area, a second pixel area,and a third pixel area, the display device comprising a firstluminescence device, a second luminescence device, and a thirdluminescence device in a one-to-one correspondence with the first pixelarea, the second pixel area, and the third pixel area, respectively,wherein: each of the first to third luminescence devices includes afirst electrode, a second electrode, and a quantum dot layer containinga quantum dot which is disposed between the first electrode and thesecond electrode, and has been surface-treated with a polar material;and the polar material is an organic compound having an amino group anda silane group, or a thiol group and a carboxyl group.
 18. The displaydevice of claim 17, wherein: the polar material is at least one selectedfrom the group consisting of 3-aminopropyltriethoxysilane (APTES),3-aminopropyltrimethoxysilane (APTMS),N-(6-aminohexyl)-3-aminopropyltrimethoxysilane (AHAPS),N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane (AEAPS),3-aminopropyldimethylethoxysilane (APMES), and3-(N,N-dimethyl)-aminopropyltrimethoxysilane (DMAPS), or the polarmaterial is at least one selected from the group consisting ofmercaptoacetic acid derivatives, mercaptopropionic acid derivatives,mercaptobutyric acid derivatives, and mercaptovaleric acid derivatives.19. The display device of claim 17, wherein each of the first to thirdluminescence devices further comprises: an electron transporting regiondisposed between the first electrode and the quantum dot layer; and ahole transporting region disposed between the quantum dot layer and thesecond electrode.
 20. The display device of claim 17, wherein the firstluminescence device emits red light, the second luminescence deviceemits green light, and the third luminescence device emits blue light.